Rob Diaz de VillegasWFSU-TV

Last week on our Water Moves EcoAdventure, we showed images of polluted waterways south of Tallahassee. We in this area benefit from a large amount of protected lands, which surround us with scenic views as well as protect many of our rivers and streams. But Tallahassee itself is fairly urban; our paved roadways move pollutants into drainage ditches and sloughs instead of letting them sink into the ground to be filtered by the aquifer. Some waterways are more affected than others. Our lakes and rivers provide us with fresh fish and recreation; when they become compromised by algal blooms and other pollutants, they affect the health and economy of the communities around the resources.

With that in mind, I’ve compiled this list of lakes in the area, with data for each on cleanliness and safety concerns. We’re looking at three things:

Nutrient load for each lake. We’ll link to a PDF of a report published by Leon County Public Works, which was compiled by Johnny Richardson (who we interviewed in the Water Moves video). I can’t link to the individual pages, but I will list them with the link back to the document if you’re interested in reading more.

Toxic algal blooms. DOH has an Algal Bloom tracker which lists three locations in Leon County. During the rainy season, these blooms will get flushed, but the locations listed have had persistent nutrient problems and are still a risk to bloom when the weather dries.

Nutrients: The report we cite was issued by Leon County in 2011. The report uses a measurement developed by FDEP, called a Trophic State Index, to determine the health of a waterbody. It’s a formula that weighs nutrient levels (phosphorous, nitrogen, and chlorophyl a), with a score of 60 or higher denoting an impaired waterbody (40 for clearwater lakes, which are lower nutrient systems). Lake Iamonia’s scores over the last few years are well blow that, averaging in the low 40s (chart on Page 64).

Fish Safety: According to the DOH Freshwater Fish Guide, this is a fairly healthy lake. Florida lakes and rivers are considered to have low to medium mercury levels, so the guide puts limits on how much they recommend that an individual eats. They recommend most fish caught in Iamonia be eaten no more than twice a week (page 16) for most species (slightly less for children and pregnant/ trying to get pregnant mothers). This is as high as they go for any Florida waterbody.

Other Concerns: As we learned during the Red Hills Water EcoAdventure, the lake’s sinkhole was impounded in the 1930s. While the dam has been removed, there is ecological damage that could take generations to fix.

Lake Miccosukee (6,257 acres. It forms the northeast border of Leon County, but is located in Jefferson County)

Nutrients: It averages in the 50s on the TSI index (page 174-5); below the impairment level but higher than Iamonia due to an elevation of one particular nutrient, chlorophyl a. This may be related to the dam constructed around its sinkhole in 1954. It’s a story you see on many area lakes, playing out slightly differently on each. Impounded lakes end up with floating islands of vegetation, tussocks, which block the sun and add organic material to the sediment. This vegetation might be responsible for the elevated chlorophyl.

Fish Safety: The high amount of vegetation on the surface has reduced the amount of dissolved oxygen in the water, and so there aren’t a lot of fish in the lake. Of the two species listed on the DOH document, it recommends no more than twice a week (page 18) for bluegill and once a week for largemouth bass. This is typical for bass throughout the document; some fish store more mercury in their fat cells.

Lake Jackson (4,000 acres)

Stormwater runoff in Elinor Klapp-Phipps Park. This plot of land is adjacent to Lake Jackson, which is why it was purchased by the Northwest Florida Water Management District. Having protected land next to the lake reduces urban runoff into it.

Nutrients: Over the course of the last few years, the color of the lake’s surface has clarified, so it technically qualifies as a clearwater lake with a lower TSI threshold. As such, it would be considered an impaired lake, averaging in the 40s on the TSI index (page 95). The report questions using the lower threshold, citing “the dynamic nature of the lake and the recent drought” (pages 95-96). Part of the change in color is attributed to changes in stormwater management, which have reduced runoff to the lake.

Tall Timbers’ Georgia Ackerman teaches me to stand up paddleboard on Lake Hall, as part of our Red Hills Water EcoAdventure.

Nutrients: Lake Hall is one of the cleanest lakes in Leon County, averaging in the high 20s(page 91) on the TSI. As a clearwater lake, it’s threshold for impairment is 40. Lake Hall is partially located in Alfred B. Maclay Gardens State Park. There are some restrictions on the use of motors on Lake Hall.

Middle Leon County

Lake Lafayette

Dead vegetation on the surface of Lower Lake Lafayette. The segmentation of the lake in the early twentieth century has affected its ability to “dry down.” Many Leon county lakes naturally empty into sinkholes every few years, and the plants and animals that live in the lakes have adapted to and thrive in such conditions. Impounding Lake Lafayette has caused floating mats of vegetation to form on its surface, disrupting the lake’s ecology. Clearing the vegetation is an involved and expensive process.

As we learned on our Lafayette Heritage Trail Park EcoAdventure last year, the historical Lake Lafayette has been segmented into four smaller lakes by earthen dams. As with other lakes in our area (Iamonia, Jackson, and Miccosukee), its sinkhole was separated to prevent the lake from draining. The sinkhole is in Upper Lake Lafayette. The other lakes are Piney Z. Lake, the Alford Arm, and Lower Lake Lafayette (which feeds the St. Marks River). Impounding the lake has resulted in tussocks and accumulation of mucky sediment, as in the other lakes.

This lake is north of the Cody Escarpment and is considered a part of the Red Hills. I classify it differently because of its more urban setting.

Nutrients :

Upper Lake Lafayette: Based on its color, its TSI index is 40. It regularly exceeds that threshold, averaging about 50 TSI(page 132) and going into the 90s in 2005. This part of the lake drains housing developments and is adjacent to the Walmart/ Costco shopping center on Mahan Drive.

Alford Arm: Alford Arm drains the Miccosukee Greenway, the J.R. Alford Greenway, and the Welaunee Plantations. It’s threshold is 60 TSI, and its average TSI is in the low 40s (page 140).

Lower LakeLafayette: Its threshold is 60 TSI, and it has only exceeded that once in the last ten years, in 2004. While its score came perilously close to 60 for a couple of years after that, since 2006 its TSI score has dropped into the low 40s/ upper 30s (page 146).

Fish Safety: Only Piney Z. is listed, recommending no more than two a week (page 27) for all species. I’m not sure if this data was collected before or after the toxic algal bloom.

Lake Talquin (6,963. It is a larger lake than Iamonia, but it is an artificial lake created by a hydroelectric dam on the Ochlockonee River)

Nutrients: The lake averages in the low 50s on the TSI index, below its threshold of 60 (page 253).

Fish Safety: Two a weekfor all species except largemouth bass (page 22).

Lake Talquin is recognized as an outstanding body of water by the Florida Department of Environmental Protection.

The Bradford Chain of Lakes

The Bradford chain is comprised of three connected lakes: Bradford, Hiawatha, and Cascade.

The first time I ever paddled a canoe or kayak was in my mid-twenties, at the FSU Seminole Reservation on Lake Bradford. Wanting to get my son Max out on the water at a younger age, I took him there last year.

Nutrients:

Lake Bradford: It averages in the 40s on the TSI index (page 191), which is below its threshold of 60. It has risen since 2006; prior to then it had averaged in the 30s (the report theorizes that this may be due to runoff created by Tropical Storm Faye in late 2008). Lake Bradford sits between the FSU Seminole Reservation and the Tallahassee Museum, and drains the residential area between Orange Avenue and Capital Circle.

Lake Hiawatha: The lake averages in the 40s on the TSI index (page 194), below its threshold of 60. While paddling the corridor between Lake Bradford and Lake Hiawatha, you pass the Florida panther enclosure in the Tallahassee Museum.

Lake Cascade: Lake Cascade Averages in the low 30son the TSI index(page 197), well below its threshold of 60. This lake is susceptible to drought. The report lists gaps where water could not be collected due to low levels.

Fish Safety: Not listed.

South Leon

Lake Munson (255 acres)

The sad thing about Lake Munson is that it is really an attractive lake. It is believed to have once been a cypress swamp, that had its water impounded in the 1800s. It is still ringed by cypress trees.

Nutrients: “The lake has a history of severe water quality and ecologic problems including fish kills, algal blooms, floating aquatic vegetation, high nutrient and bacterial levels, low game fish productivity, sediment contamination, and depressed oxygen levels (Maristany and Bartel, 1989)” (page 206). Lake Munson routinely exceeds 60 on the TSI index (page 208), though it will dip below the threshold seasonally, sometimes for over a year. When I visited the lake earlier in the month, Johnny Richardson told me that the heavy rain we’ve gotten does help to flush the lake. The DOH Algal Bloom tracking tool reports toxic blooms on both Lake Munson and on Munson Slough to the north of the lake (the slough also continues to the south through the Apalachicola National Forest, partially draining into Wakulla Springs). The tool merely reports that there have been blooms recently. The blooms had washed away when I visited, but Mr. Richardson expects them back in the summer.

Fish Safety:The DOH guide recommendsno more than twice a week for all species but black crappie (page 19). This is their recommendation based on mercury level. There is a warning for PCBs (Polychlorinated biphenyl, an endocrine disruptor, page 35). It recommends, based on PCB concerns in largemouth bass, no more than one meal a month. That’s if you’re willing to put any amount of it in your body to begin with.

AdditionalConcerns: At several points over the last ten years, Lake Munson has exceeded the acceptable levels of fecal coliform (page 216). Fecal coliform is caused by human or animal waste, and an excess could be due to septic tank failures or sewage overflows.

So that’s the good, the bad, and the ugly of our local lakes. There is plenty of good recreation and fishing to be had, but it is helpful to know which bodies of water present potential health risks. Most of the problems are preventable, if people are willing to make changes. Some of the changes aren’t too much of a burden, and others have benefits beyond reducing personal pollution. We’ll look at some of those in the coming weeks.

Rob Diaz de VillegasWFSU-TV

Teams of children try to remove water from a central pool without stepping over a red line.

I was happy to hear that our station was going to create a game where children would learn about the movement of water in our area. Not enough people know where their drinking water comes from and where it goes. The short answer is: from the earth, and back into the earth. The longer answer led me to the specific place that drains FSU, FAMU, TCC, and Tallahassee’s downtown. The water we drink and the water we use for recreation in lakes, rivers, and on the Gulf, that water is all part of a system. There are subsystems within that system. There is the manmade network of pipes and treatment facilities that take water from the aquifer and place it in our homes; or the aquifer itself, replenishing with rain and feeding springs.

With Water Moves, WFSU aimed to teach children about systems thinking. Our local game is part of a larger initiative from PBS Kids Digital, which wanted something that had kids running around to compliment an upcoming computer game. Six teams of six kids had the same goal, to fill their buckets (houses) from a central pool (the aquifer) using tools they bought by earning points. Jamie Shakar from the City of Tallahassee then talked with them about the actual system, through which rain sublimes into the ground and is filtered through sand, clay, and ultimately limestone, finally reaching the sites where the city pumps our water.

In our Red Hills EcoAdventure, I made a connection between sinkholes in our lakes and our drinking water . Technically speaking, the water we drink does not come from surface water (lakes and rivers), but from groundwater (filtered and made clean as it makes its way down). To our second presenter of the day, though, all water in the aquifer is connected and must be protected.

Where Munson Slough flows into Lake Henrietta.

Karen Rubin is with the City of Tallahassee’s TAPP (Think About Personal Pollution). She showed that, as rain falls and filters through the ground into the aquifer, it also travels off of lawns and parking lots and down streets, looking for a low point. As this is how water flows, the low points tend to be lakes. For the most urban areas within Tallahassee, that low spot is Lake Munson. It is the most compromised body of water in our county. It is fed by Munson Slough, which runs through Lake Henrietta along the way. I visited Lake Henrietta, where the county has built barriers to catch some of our trash and keep it out of Lake Munson. What I saw, and smelled, kind of surprised me. I thought that the Munson Watershed’s problems would be more subtle, evidencing themselves in water quality readings on a table in a report. I was wrong.

What is being carried into Lake Munson? Think of our roadways, and all of the car exhaust that hits it. Do you notice a little puddle under your car when you run the air? And in and around our homes. People fertilize their lawns and vegetable gardens (As we’ve covered before, an excess of nitrogen from fertilizers ends up feeding algae, which blooms, sucks up oxygen and kills aquatic life). We use pesticides to kill those ant piles that pop up everywhere. We pressure wash our houses with chemicals. Water washes off of our lawns, picking up these chemicals and compounds as it drains to that low spot in our watershed.

Now, if Lake Munson was the final resting place of these pollutants, we might well say “Munson can take one for the team” and let it collect our refuse. We have so many great lakes and rivers already. But Munson Slough continues southward from the lake. It disappears down Ames Sink and a percentage of its water end up in Wakulla Springs.

An anhinga, surrounded by hydrilla, on Wakulla Springs. By occupying the space where water runs against vegetation, hydrilla may have prevented apple snails from laying their eggs and ultimately depriving limpkins of food.

Wakulla Springs has an outline of a limpkin on its sign. And while some comments in a 2012 post regarding limpkins offer some hope for their return, that bird disappeared from the park in the 1990s. No definitive cause has been determined, but many look at invasive hydrilla as a culprit. Fed by excess nutrients, it is a major presence in Wakulla Springs. So much so that it encroached upon the bases of plants where apple snails lay eggs. When its source of food disappeared, there was no reason for the bird to stay.

Johnny Richardson is a water quality scientist with Leon County. He told me that while 11% of the nutrients in Wakulla Springs are known to come from streams and sinks, they don’t know exactly how much comes from the Munson system.

A television lies in algae just downstream of a dam on Lake Munson. From here, the lake flows into Munson Slough, through the Apalachicola National Forest, and into Wakulla Springs.

It’s hard to say how much one leaky car or one overzealous gardener might degrade our beloved natural resources. Tallahassee can take the blame for Lake Munson, accept that it has some negative influence on Wakulla Springs, and feel okay that it isn’t contaminating seafood in St. Marks. What we do know is that we can make the problems better or worse. We can control this.

Over the summer, we’ll look at ways to reduce our personal pollution. For instance, instead of leaving a TV and its toxic innards on the curb for a few days, or heaving it into a lake, you can take it to Leon County’s Solid Waste Facility. It’s a little out of the way, but maybe you were going to Tom Brown Park or Walmart anyway?

Also over the summer, we’ll get back to the fun EcoAdventures. Also, Randall Hughes and David Kimbro will look back at the research into salt marsh, oyster reef, and seagrass bed ecology that we’ve been following over the years. Our area has some amazing ecology, and there are places we haven’t been and connections we haven’t yet made. I never tire of learning how it all works.

Four years ago, we traveled out into the oyster reefs of Alligator Harbor with Dr. David Kimbro. It was both the start of an ambitious new study and of our In the Grass, On the Reef project. Last June, we went back to those reefs with Dr. Randall Hughes as she, David, and their colleagues revisited study sites from North Carolina to the Florida Gulf. In 2010, they sampled the reefs with nets and crab traps, and harvested small sections of reef. This more recent sampling, which unfolds in the opening scenes of our recent documentary, Oyster Doctors, was conducted with underwater microphones. Randall explains how sound became a tool in further understanding fear on oyster reefs.

The research in the following post was conducted while Randall and David worked at the FSU Coastal and Marine Laboratory.

To answer #1, we paired up with Dr. David Mann. Dr. Mann is an expert in bioacoustics, and particularly in evaluating whether marine critters (primarily fish) can hear different sounds. We modified his methods slightly to accommodate our mud crabs – basically, we needed to immobilize the crabs on a ‘stretcher’ so that we could insert one electrode near the crab’s antennae, and another in the body cavity to pick up any background “noise” the crab may be produce that was not in response to the acoustic stimuli. Although it looks like mud crab torture, all the crabs survived the experiment!

What did we find? The crabs had a neurological response (i.e., they “heard”) a range of frequencies. They certainly wouldn’t ace any hearing tests, but if a sound is low- to mid- frequency and relatively close by, they can likely hear it. They do this using their statocyst, a structure containing sensory hairs that can detect changes in orientation and balance, and in this case, can detect changes in particle acceleration associated resulting from the acoustic stimuli.

Although cool to someone like me who is fascinated by marine biology, many of you are probably thinking “So what?”. And for that, we turn to the second part of our study, where we tested whether mud crabs change their eating habits in response to the songs made by their fish predators. We compared the number of juvenile clams that crabs ate when we played them either a silent recording or a recording of snapping shrimp (a common organism on oyster reefs that doesn’t eat crabs) to the number of clams that they ate when we played them recordings of songs from 3 fish that DO eat mud crabs – hardhead catfish, black drum, and toadfish. Apparently catfish and black drum songs are the same to a crab as the Jaws theme song is to me, because they hunkered down and did not eat nearly as many clams when they heard the calls of those two predators.

Phil Langdon feeds a catfish in an iteration of a mud crab hearing experiment. They had already noticed that mud crabs were eating less when they heard sounds made by catfish and other predatory fish. Here, they sought to measure whether the response was more intense with chemical cues (pumped via those tubes into tubs), or predator sounds (played from underwater speakers).

So, now we know that mud crabs can hear, and that they don’t eat as much when they hear some of their predators. But we also know from our earlier experiments that these same crabs don’t eat as much when exposed to water that hardhead catfish have been swimming in, most likely because they can “smell” chemicals in the water that the fish give off. So which catfish cue generates a stronger response – sound or smell? Turns out that both cues reduce crab foraging and to about the same degree, although in our experiment the effects of catfish songs were slightly stronger than the effects of catfish smell.

So what’s the take-home message from this work? For one, it highlights that we still have a lot to learn about the ocean and the animals that live in it – we (and others) have been studying these mud crabs for years and never thought to consider their ability to use one of the 5 major senses! In addition, it’s a reminder that in studying the “ecology of fear”, or the effects that predators have on their prey even when they don’t eat them, we need to remember that few predators are silent, and the sounds that they make could be important cues that prey use to escape being eaten. And finally, it demonstrates that science can be really fun!

This material is based upon work supported by the National Science Foundation under Grant Number 1161194. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Watch and listen: what does a Wilderness sound like at night?

Rob Diaz de VillegasWFSU-TV

It seems like a good premise for a movie: Under a full moon, on Friday the thirteenth, a group of people wander in the Wilderness. You could be a part of this movie on Friday, June 13 (8 pm), as Haven Cook of the U.S. Forest Service leads a hike into the Bradwell Bay Wilderness. It’s one of a series of events being held in the Apalachicola National Forest to celebrate 50 years of the Wilderness Act. Passed in 1964, the act designated certain protected areas as Wilderness.

So how is a Wilderness any different than any other protected land? We are surrounded by the Apalachicola National Forest, St. Marks Wildlife Refuge, Wildlife Management Areas, state parks, and large greenways. There are some waterways near here where you could spend hours and not see many signs of civilization. It’s already plenty wild around here, right?

A Wilderness area restricts the use of motorized or mechanical equipment. Not even a bicycle or, as the sign at the trailhead states, a hang glider (the WFSU hang glider was sadly left behind in our vehicle). No structures can be placed on the grounds, though any that were historically found there can remain. It has to, as the act states, retain “its primeval character and influence, without permanent improvements or human habitation.” Section 2(c) of the 1964 Wilderness Act. The primary force affecting the Wilderness must be nature, not man. The idea is that you can go there and experience total solitude in nature, and that means freedom from the buzz of a chainsaw or seeing that glider over your head.

The primary man made feature of the Bradwell Bay Wilderness is the unpaved trail that runs through it. In the pine flatwood area leading up to the swamp, it was an old road that Haven believes might have led to an homestead, likely belonging to the Bradwell family. It has a ditch running along either side of it, where you can occasionally see pitcher plants growing (as we learned a few weeks ago in another part of the Apalachicola National Forest, carnivorous plants love ditches and their found-in-nature equivalents). There is an old bridge that takes you over a small creek that drains into the Sopchoppy River. While they won’t put any forest roads through the Wilderness (its boundaries are formed by forest roads), the trail is maintained as a part of the Florida National Scenic Trail. In places, that doesn’t mean much more than an orange blaze on a tree.

Some Wilderness areas don’t even have that level of human footprint. The Mud Swamp/ New River Wilderness, also in the National Forest, is one. In general, Wilderness areas in the Eastern United States tend to be smaller and less isolated than in the less populous Western half of the country. In 1975, congress passed the Eastern Wilderness Act, which created the Bradwell Bay Wilderness. This act acknowledges that “additional areas of wilderness in the more populous eastern half of the United States are increasingly threatened by the pressure of a growing and more mobile population, large-scale industrial and economic growth, and development and uses inconsistent with the protection, maintenance, and enhancement of the areas’ wilderness character.” Section 2(a)(3) of the Eastern Wilderness Act.

Often in the Forest, you’ll see these burnt woody shrubs among the palmettos between the pines. Longleaf and slash pine can tolerate fire and palmettos grow back, but hardwood trees do not fare well in this ecosystem.

It should also be noted that, though the area is intended to be as much as possible like it was when this country was founded, the pine flatwood area is a second growth forest where you can still see rows of planted slash pine. Like many of the places that we consider wild around here, it had been cut at some point. It is, like the rest of the forest, maintained by prescribed fire. This is to replicate the fire regime that occurred naturally before the area was settled by Americans. Since the Wilderness won’t burn every three to four years without assistance, The Forest Service keeps the “primeval” character of the area by simulating the regime that had occurred there.

We didn’t make it to the swamp, as we were previewing the full moon hike, though a little earlier to get more shots in the light. We’ll have to save that for another EcoAdventure. If you’re going on June 13, the sun will set within the first hour of the hike, and there will be mosquitos. And also ticks. This isn’t out of the ordinary for a hike at this time of the year. But when the moon comes out, you’ll see the Wilderness entirely differently. More strikingly, it will sound different. And, you know, there’ll be that slasher movie plot thing happening.

Coming Up

One value of the Bradwell Bay Wilderness is that, without motorized vehicles or human made structures, the stormwater runoff flowing from it to the Sopchoppy River is clean. We spend a lot of time on our EcoAdventures visiting well preserved, healthy land and water resources. On our last EcoAdventure of the season, we’re going to visit some places where you don’t want to touch the water or eat fish from it. We’re talking drinking water (which is clean) and stormwater. Wait until you see the bodies of water that collect our runoff.